The present invention relates to compositions and processes for making polyurethane foams. More particularly, it relates to compositions and processes incorporating compounds for enhancing the effectiveness of hydrohalocarbon blowing agents in making polyurethane foams.
The manufacture of rigid polyurethane foams has been significantly impacted by restrictions on the use of certain prior art blowing agents, which may be environmentally harmful. Although new, more environmentally acceptable blowing agents have come into use (typically hydrohalocarbons), these are generally not as effective as those commonly used previously and there is therefore a continuing need for enhancements in the process of making rigid polyurethane foams and/or in the properties of the foams themselves. The present invention addresses that need with compounds which are believed to enhance the effectiveness of blowing agents used in making rigid polyurethane foams.